Tooling Article

Machining Moves Made to
Quicken Speed to Market

Behind
every great pressroom is a great toolroom, equipped and staffed to move
new dies from the design center efficiently through production, and to
also return production dies requiring maintenance back to the presses
in a timely manner. Toolrooms also are tasked with supporting assembly
and welding operations, by manufacturing jigs and fixtures.We
interviewed managers at three metalforming companies to learn how each
is equipping its toolrooms to be the perfect partners to their
production-manufacturing operations. Part 1 of 3.

This
isn’t a car magazine, so I don’t get to test-drive the flashy new
models that lit up the stage at the Detroit auto show—models like the
recently introduced Camaro convertible. So rather than being part of
the media frenzy surrounding that particular car, and typing up flashy
prose describing its teeth-rattling performance and wind-in-your-hair
exuberance, I decided to trace some of the behind-the-scenes
manufacturing excellence that has made this dream car a reality.

My
Camaro-manufacturing journey took me to a metal stamper known primarily
for providing fineblanked throttle plates, lock hardware and similar
parts which, virtually overnight, morphed into becoming the sole
manufacturer of completely assembled hardware systems for the
convertible top on the new Camaro.

“As
the Tier Two supplier to Magna for the convertible-top’s steel
substructure, we’re busy running 28 new dies and assembling 41 parts in
all, including bushing insertion, riveting, welding and tapping,” says
Principal Manufacturing toolroom manager John Brazzale. I managed to
hit the plant’s production floor (in Broadview, IL) during launch week
for the Camaro convertible project, so it’s newly outfitted assembly
room, where all of the stampings, fasteners et al come together, was
teeming with activity. What I missed, of course, was the flurry of
toolroom activity over the last several months that brought the company
to this point.

Toolroom Runs Flat Out to Make Fixtures, Gauges

“Our
toolroom designed and built all of the assembly fixturing for riveting
and welding,” says Brazzale, “a huge project that included gauging and
restraining fixtures for our coordinate-measuring machines. Also on the
books for this project were design and build of four new fineblanking
dies (the rest of the stamped parts are made on conventional
progressive tooling that Principal outsourced to other die shops). Our
toolroom load more than doubled.”

Long
before the Camaro convertible hit the streets in February 2011, it
created quite a stir on the auto-show circuit. Among its numerous
selling points: refinement of the car’s top, which had designers
seeking a solution to the ever-present rib lines that have plagued
every convertible-top designer for decades…until now. Thanks in part to
the work of Principal Mfg., the top, wrote one car reviewer, has a
“smooth, taut appearance that

A Fadal vertical-machining center makes quick work machining a die block in the Principal Mfg. toolroom.

retains the vehicle’s sleek roofline.”

The
Camaro project now has the pressroom and assembly room at Principal
Mfg. turning out 1100 complete units/week—by anyone’s calculations,
that’s a lot of stampings and assembly time. Success on a project of
this scope only came thanks to the company’s continuous improvements
made in its toolroom over recent years—to its die-build procedures, as
well as the addition of new CNC wire-EDM machines.

“We
invested in new wire-EDM technology (a pair of Mitsubishi FA-20S
machines) to increase capacity,” shares Brazzale. Comparing the new
technology to old, he says that “we achieve the same surface finish on
our die blocks and other machined components, but we get there 15
percent faster than we used to. For example, cutting a die block that
once required five passes now takes only three. Our throughput has
increased greatly, and hence so has our speed to market with new
projects.”

State-of-the-Art EDM Pays Off

The
Mitsubishi FA-20S offers x-y-z axis travel of 19.7 by 13.8 by 11.8 in.,
and maximum size of 41.3 by 31.5 by 11.6 in. Features include 16-step
programmable flushing control, 3D graphical programming, a digital
500-W AC servo-drive system and the ability to make large tapers—45
deg. per side when using special guides, flush cups and Mitsubishi’s
Angle Master option.

More from Mitsubishi promotional material:

“Generator power

Wire-EDM
work on the firm’s newest machines from Mitsubishi has become at least
15 percent more efficient thanks to state-of-the-art technology.

and flushing pressure are automatically adapted for the processing
conditions, optimizing the cutting speed and minimizing the risk of
wire break at the same time. This decreases throughput time and
permanently reduces operating costs.

“A further highlight is
the Technology Master function, which automatically ensures that the
processing of complex workpieces, with differing thickness or with
longer distances to the lower flushing nozzle, is performed with
ultimate precision.

“The standard
HSS-AE (high speed surface anti electrolysis) generator reduces the
impairment of surface hardness by electrolysis or electrochemical
corrosion, respectively, to a minimum. Your advantages of this patented
system: No pitting even for long processing duration. The new generator
significantly reduces problems caused by poor wash-outs of removed
materials, such as binding agents of sintered materials and thermally
induced micro cracks. High quality surface finishes mean reworks are
reduced to a minimum.”

To Principal
Mfg., this translates into faster production, speed to market, expanded
capacity and the ability to meet the requirements of game-changing
contracts like the Camaro job entrusted to it by Magna.

Hard Milling on Fineblanking Dies

Another
move made in the toolroom to quicken speed to market was moving some
work a from sinker EDM and to CNC hard milling with carbide cutters.
Specifically, the toolroom now hard mills most of its stinger
rings—impingement rings found on most fineblanking tools to control
material flow during forming. Machining the rings cuts processing time
in half, and in the pressroom the tools last 30 percent longer between
maintenance cycles.

“Our lead time for new dies—from design through build—has shrunk from 11 to 12 weeks down to an average of
8 weeks,” Brazzale says, “due to incremental improvements such as the

The
assembly room at Principal Mfg. dedicated to building the substructure
for the Camaro convertible top includes dozens of new assembly fixtures
and jigs, like the one shown here.

move
to hard milling and to our new wire-EDM equipment. We’re doing as much
work on the tools as we can before the toolmaker ever receives the die.
Typically all he has to do, then, is slide in the pins and bushings and
anchor them, and assemble everything, rather than having to spend a lot
of time grinding blocks and such.”

The firm builds standard
fineblanking die sets to 26 in. square, 3.5 in. thick top and bottom.
Of its 300 employees, 24 toil in the toolroom.

“Eight
years ago we were building dies the ‘old-fashioned ,’” Brazzale
continues. “We’d transfer holes from die blocks to the die set,
manually line it all up and rely on drill presses. Now we put the die
set and heattreated blocks in the machining center and locate off of
the leader-pin holes and machine all of the holes for the complete
tool, so that everything is mounted off of the machining center and
aligned perfectly top and bottom. And rather than press pins into the
die set we press bushings so that as they wear we can easily replace
them. As a result we’re holding tighter tolerances on our dies, and
they run better in production.” MF